Interlocking system for railroads



Jan. 9, 1934. s. N. WIGHT INTERLOCKING SYSTEM FOR RAILROADS Filed July 11, 1930 INVENTOR BY 5 32%; /4 g f ORNY Patented Jan. 9, 1934 1l,dd2,788

ATENT @FFlCiE 1,942,788 lNTERL-GQKING S1!S'EEIVI FGR EAILROADS Wight, Rochester, N. Y, assigncr to Gmeral Railway Signal Company, Rochestor, N. 5..

Appiication July ll, 19%. Serial No. 467,222

11 Claims.

This invention relates to manually controlled power operated interlocking systems for railroads, and mote control "e particularly to a system of rea power operated switch machine, and is an improvement upon the invention disclose in my earlier application Ser. No. lfilfllsfiledlfebruary 27, 1930.

I in interlocking systems of the mechanically in terlocked lever type, and types of systems in 7 which the levers are locked by suitable approach look .a or detector locking means, the operator course not able under unsafe conditions to shove the lever, and for that reason cannot tentatively set up operating condition which may later become effective due to the clearing up of conditions which formerly looked the lever. In other words, in systems such as just mentioned, the operator cannot initiate a control until it is proper for such control to become effective. In

' accordance with the present invention it is proposed to leave the levers unlocked at all times, and to provide such interlocking or approach or detector locking as may be required to be carried out electrically and irrespective of movement of the lever, and in accordance with this invention it is proposed to provide simple electrical means for effecting approach and the detector locking controlwhich requires movement of the control lever while the approach and detector locking device energized and ineitective, and this is carried out without mechanically restraining the movement of the control lever. Another object of the present invention is to provide a simple and novel organization of parts and circuits to obtain the necessary and desirable indications and safe controllability of a power operated switch and its associated signals.

More specifically it is proposed to control the distant trafiic controlling device, such as a switch machine, through the medium of a snap action or stick type relay, and to provide suitable time limiting means associated with the lever in such a way that the lever may control the snap acting relay only for a short period of time a-ter each operation thereof, so that if energy is prevented from flowing to such snap acting relay by reason of approach or detector locking the snap acting relay cannot operate when the approach and detector conditions clear up, even though the lever is left in the operated position.

Other objects, purposes and characteristic features of the present invention will in part be obvious from the accompanying drawing and will in part be more specifically described hereinafter.

In describing the invention in detail reference will be made to the accompanying drawing, in which the portion in the dotted rectangle represents the apparatus located in the interlocking tower, and the remaining apparatus illustrated 's located at a distant track switch on the railway system.

Structure Referring to the drawing, the track rails 1 of the railway system have been shown divided into blocks by insulated joints 2, to provide track circuits of which the detector track circuit having track relay DR and a track battery 3, and the approach track section having a track relay TR and a track battery 4, only have been shown. The siding or diverging route has been indicated by track rails 5 connected to the main track through the medium of a track switch S, which track switch is operated by a switch machine SM. This switch machine SM is controlled by the snap action, or stick type relay CR, which relay after it is operated to one of its operated positions remains there until it is operated to the other position, even though it is deenergized in the meantime.

In the interlocking tower T, conventionally shown by the dotted rectangle T, is located a lever L, having pole changing contacts 10 and 11, which contacts 10-11 supply current of one polarity or the other to the relay CR, providing the lock relay LR is energized. This lock relay LR can only be temporarily energized, because its energizin circuit includes a back contact 12 of the relay SR, and the relay SR is energized when the line relay LR is energized, so that the lock 99 relay LR may at any time only be energized until it has picked up and has again energized the stick relay SR, which stick relay when up opens its contact 12 and effects deenergization of the lock relay LR. Deenergization of the 1ockrelay LR is also dependent on the detector and conflicting route locking relay DL, which has an energizing circuit including front contacts 13 and 14 of the track relays TR and DR, respectively.

Although suitable interlocking and detector locking and approach looking for the switch machine SM may be made locally and outside of the tower T itself, suitable electric interlocking may be provided whereby the lever L Will not be effec- 105 tive to control the switch machine SM unless the Apparatus for this purpose has been conventionally shown by the front contact 16 of the detector and conflicting route locking relay DL from which it appears that the lock relay LR can only be energized after the signals of all, conflicting routes stop position. In order to get a more clear 'understanding of the features of the system, the essential apparatus of which only has been illustrated, the remaining apparatus such as indi-v eating lamps indicating the'conditionof "wayside signals and the switch machine and the occupancy of various trackcircuits having been omitted, it is believed expedient to consider the operation of the system.

Operation 'Let us assume that theoperatorin the tower T wishes to operate the switchniachine SM to the take-siding position, andin order'tofldo" so "operates the lever L to the dottedposi'tien. This movement of the lever reverses the potential'applied to the stick relay'SR, so that the current flow in the Winding of the stick relay SR and the flux resulting thereirom' must reversefand the relay SR is so'designed that 'it willas'sume its deenergized position in response to'thisrever'sal of 'fiuX in the core of the relay'SR. Withthis stick relay SR once deenergized andits stick contacts open, it will remain "'deenergi'zed until eith r the back contact 21 of the relay DL or the front contact 22 of the relay LR is closed.

' "With the stick relay SR deener'gi'zed, andbn 'the assumption that there is 'no approaching train and the track'relays' TR andD R are ener ized, and also on the assumption that none of the confiicting signals assume the clear position, as

' manifested'by' the contacts 17 when assuming the closed position, the lock'relay LR is energized through the following 'circuitzbeginning at,

the terminal B of a suitable battery, 'frontcontact 16 of the relay DL, wire'23, back contact 12 of the relay SR, wire 24, winding of the relay LR to the other terminal C of said battery.

With lever L now assumingthe dotted position and with the lock relay LR energized the control 'relay CR may be operated to tl1e"r 'ei /erse dotted position through the following circuit:-begin- "ning at the positive terminal of the'battei'y 25, 1'

wire 26, contact 10 of the lever L, wires'28 and '29, front contact of'the relay'LR, line 'wire31,

winding of the relay CR, line wire 32, front contact 33 of'the relay LR, wires 34 and 35, contact 11,'wire 36, andback to the'n'egative terminal of the battery 25. The circuit just traced need only "be closed momentarily to effect operation of the control relay CR, and operation of theco'ntrol relay CR to the dotted position eifects operation of the switch'machineSM to the take-sidingposition, through the medium of the reverse wire R included in a circuit readily traced in the draw- 'ing.

With the lock relay LR energizedth'e stick relay SR is picked up through the following circuitz-beginning at the positive terminal of the battery 25, wire 26, lever'contact l0, wires 28, 40,

41 and 42, front contact 22 of the lock relay' LR, wires 43, 44 and 45, winding of the relay SR, wires 46 and 35, contact 11 of the lever L, wire 36, and back to the battery 25. The closure of this circuit will pick up the stick relay SR, as a to operate the s witchmachine s is only effective ito operat e" sucliswitch' machine if such lever is result of which the stick contact 20 will shunt the contact 22, so that this relay SR remains energized through a stick circuit readily traced in the drawing even though the relay LR drops and its contact 22 opens. Picking up of the stick relay SR breaks the energizing circuit of the lock relay LR. at the back contact 12 of this stick relaySR, so that the lock relay LR is again deenergized after a very short period of time, and with the contacts 30 and 33 assuming their retracted position the line wires 31 and 32 are shorted together through the shunting wires 46 and 47. It is thus seen that operation of the lever under normal favorable route and traflic condit'i'onswillallow the lock relay LR to be energized only for a short time, depending on the drop-away characteristic of this lock relay LR, and it" may be pointed out here that the lock relay LR is preferably slow dropping, so that its contacts remain up for say one or two seconds, and that thereafter the line circuit to the control relay CR isagain broken and is shorted by mews-esteem 47,' so' that theapplica'tion of current from'an unauthorized source wil be unable to operate "the con'trol ma CR. M p I V Let us ow' assume that 'he operator wishes to operate the switch machine SM'at a time when the appreach'androute relay DL'is deenergized. In this case operationiof' the lever L will effect 'deenergizauen'fof' the stick relay SR, but this stick relay will 'reniainfdeenergized only foran "instaintfbecauseits stick contact 20' is shunted b'yf the'back'contact'21 of theiapproach and route 'rela'yDI'J, so that, if thereafter the approachland route"relay'DL":picl s "up, the "control relay CR will not be operated, because thestick relay SR is energized and its" contact 12 prevents energization"'of the lock'relay LR.

It "isth'usseenthat' i'operation' of the lever L operated"underinon conflictihg' route and favor- "able'tralfic conditions insofar as the movement "of a train toward the track switchS is concerned. In'otli'er words, the effect of moving the lever "Lisitemporary, and corresponds inthis respect to'" a lock'lever in that the attempt to operate jalocked'lever: when it is improper to operate such leter'has'no'effectupon the'future control exertablefb'y lsuch lever. Furthermore, the time "period? through which movement of the lever L 'is effective to control the distant control relay CR isindependent of the rapidity at which the leverismovedfrom oneposition to the other,

"this'beca use the stick "relay "SR is dropped by reversal of polarity of the current applied thereto rather than'by momentary deenergization of the relay, and'this stick relay SR assumes its deenergiz'ed condition in response to each operation of the lever L from one extreme to'the other extreme position.

Itis 'of course understood that the contact 17,which may comprise'any number of contacts in series each of which is closed when the sigjin'al itrepresents is at'stop,'may be'omitted from "the circuit of the detector and route relay DL,

such'protection when the contacts 17 are omitted being "obtainable locally, either through the medium of the control relay CR'or through the circuits for controlling the switch machine SM, by suitable checking contacts closed only when the signals of conflicting routes are at stop.

Also, if desired, front'cont'acts of the relay SR may be included in the wires 29 and 34, so that U relay CR is not controllable by the lever L if the t relay SR is deenegized by reason of an unauthorized break in its energizing circuit, the dropaway period of the relay allowing sufficient time to control the relay CR.

The hands-cff signal l-IO, preferauly comprising a signal lamp, is energized when the 'ector and route relay BL is in its deenergized tion, so that the operator is at all times advised whether he may expect any results to be obtained from the operation of his lever L, this sin e for reasons heretofore given operation or" the lever L at a time when this relay BL is deenergized is of no avail, and the control relay CE is not operated by the lever L under this condition. Obviously, instead of employing the hands-off signal lamp HO, a lamp illuminated only when the detector and approach relay DL are deenergised may be employed in which event the illumination of such signal lamp will tell the operator that there is no" electric looking or means pre venting control of the control relay CR by the lever L.

Having thus shown and described one specific embodiment of the pres nt invention, it is desired to be understood that the particular embodiment illustrated has been selected for the purpose of facilitating disclosure of the p ncipies of the invention and the functions desired to be carried out thereby, and it is further to be understood that various other expedients for obtaining the same results may be employed, and other additions and modifications may be made to the disclosure illustrated, without departing from the spirit or scope of the present invention, except as demanded by the scope of the following claims.

What I claim as new is:-

1. In an interlocking system for railroads; the combination with a traffic controlling device; of a free mechanically non-lockable lever having two extreme positions for controlling such traffic controlling device to corresponding extreme posi tions; means for preventing said traffic controlling device being controlled by said lever under unfavorable conditions; and other means for permitting control of said trafiic controlling device by said lever which requires movement or" said lever simultaneously with favorable traffic conditions comprising; a normally energized stick relay, and a pick up circuit for said stick relay closed under unfavorable traffic conditions.

2. In an interlocking system; the combination with a traffic controlling device; of a free lever for controlling such trafiic controlling device; means for preventing said traffic controlling device being controlled by said lever under unfavorable conditions; and other means for permitting control of said trafiic controlling devi e by said lever which requires movement of said lever when traffic conditions are favorable comprising; a time element device operated in response to operation of said lever irrespective of the time consumed during operation of said lever and effective for a time only.

3. In an interlocking system; the combination with a normally inactive trafiic controlling device; of a free lever for rendering such tramc controlling device active; means for preventing said traffic controlling device being rendered active by said lever under unfavorable conditions; and other means for permitting said trafiic controlling device to be rendered active by said lever which requires the act of movement of said lever to occur when traffic conditions are favorable comprising; a

' normally energized stick relay which is dropped by operation of said lever and is restored under unfavorable traffic conditions.

i. In an interlocking system; the combination with a traffic controlling device; of a free lever for controlling such traffic controlling device but by itself ineffective to permit said traffic controlling device to be controlled by said lever; and other means for permitting control of said traffic controlling device by said lever which requires movement of said lever simultaneously with favorable traffic conditions comprising; a slow actrelay which if energized permits control of said traffic controlling device by said lever, and a normally energized stick relay for controlling said slow acting relay having a pickup circuit including a front contact of said slow acting relay and having a stick circuit including contacts of said lever.

5. In an interlocking system; the combination with a traffic controlling device; of a free lever for controlling such traffic controlling device, but normally ineffective to directly control said traffic controlling device; and other means for permitting control of said tramc controlling device by said lever which to be effective requires movement of said lever when traffic conditions are favorable comprising; a slow acting relay which if energized permits control of said traffic controlling device by said lever, a-normally energized stick relay having a stick circuit ineluding pole changer contacts controlled by said lever and a stick contact of said stick relay, 3. back contact of said stick relay included in the energizing circuit of said slow acting relay, and a front contact of said slow acting relay shunting said stick contact, whereby movement of said lever reverses the direction of current flow in said stick relay and eifects dropping of the same and picking up of said slow acting relay effects reenergization of said stick relay and deenergization of said slow acting relay.

6. In an interlocking system; the combination with a traffic controlling device; of a free lever for controlling such traffic controlling device but normally ineifective to directly control said traffic controlling device; and other means for permitting control of said traffic controlling device by said lever which to be effective requires movement of said lever when traiiic conditions are favorable comprising; a slow acting relay which if energized permits control of said traffic controlling device by said lever, a normally energized stick relay having a stick circuit including pole changer contacts controlled by said lever and a stick contact of said stick relay, a back contact of said stick relay and a traflic controlled contact included in the energizing circuit of said slow acting relay, and a front contact of said slow acting relay shunting said stick contact, whereby movement of said lever reverses the direction of current flow in said stick relay and effects dropping of said stick relay and picking up of said slow acting relay providing said trafiic controlled contact is closed picking up of which slow acting relay in turn effects reenergization of said stick relay and deenergization of said slow acting relay.

7. In an interlocking system; the combination with a trafiic controlling device; of a free lever for controlling such traffic controlling device but normally ineffective to directly control said traffie controlling device; and other means for permitting control of said traffic controlling device by said lever which other means to be effective requires movement of said lever when trafiic lllll conditions are favorable comprising; a slow acting relay which if energized permits control of said traflic controlling device by said lever, a normally energized stick relay having a stick circuit including pole changer contactscontrolled by said lever and a stick contact of such stick relay, a lock relay which is energized if traffic conditions permit operation of said traific controlling device, a back contact on said stick relay and a front contact on said lock relay included in series in said slow acting relay, and a front contact of said slow acting relay shunting said stick contact, whereby said stick relay is deenergized upon reversal of said lever and is picked up after a short period of delay.

8. In an interlocking system; the combination with a traffic controlling device; of a free lever for controlling such trafiio controlling device but normally ineffective to directly control said traffic controlling device; and other means for permitting control of said trafic controlling device by said lever which to be effective requires movement of said lever when traffic conditions are favorable comprising; a slow acting relay which if energized permits control of said trafiic controlling device by said lever, a normally energized stick relay having a stick circuit including pole changer contacts controlled by' said lever and a stick contact of such stick relay, a lock relay which is energized if the signals of conflicting routes are at stop and traffic conditions permit operation of said traflic controlling device, a back contact on said stick relay and a front contact on said lock relay included in series in the circuit of said slow acting relay, a front contact of said. slow acting relay and a back contact of ,said lock relay each shunting said stick contact, whereby said stick relay is deenergized upon reversal of said lever and is immediately picked up if said lock relay is deenergized but is picked up after a short period of'delay if said lock relay is'energized.

9. In combination, a distant trafiic controlling device; a two position relay constructed to respond to a momentary flow of current and to remain in its last operated position until operated to another position for controlling said device; a lever for controlling said relay but normally ineffective to directly control said relay; and means for permitting control of said two position relay by said lever including, a slow acting relay having front contacts included in the circuit of said two position relay, and a stick relay controlled by said lever for energizing said slow acting relay for a time in response to the act of changing the position of said lever.

10. In combination; a railway trafiic controlling device having a normal and an abnormal condition; a free lever operable to two extreme positions and tending when in one position to cause said traffic controlling device to be operated to the normal condition and when in the other position tending to cause said trafiic controlling device to be operated to the abnormal condition; traffic controlled means for preventing said lever from controlling said traflic controlling device so long as trafiic conditions are unfavorable; and other means for preventing said lever from controlling said traffic controlling device in responseto clearing up of said unfavorable traffic conditions unless said lever is operated after such' clearing up of traffic conditions comprising; a slow acting relay, and a stick relay controlled by said lever and by said slow acting relay and in turn controlling said slow acting relay.

11. In combination; a railway traffic controlling device. having a normal and an: abnormal condition; a free lever operable to two extreme positions and tending when in one position to.

cause said traflic controlling device tobe oper-.

ated to the normal condition and when. in, the,

other position, tending to cause said traffic-con-; trolling device to be operated to the abnormal condition; and other means for preventing control of said trafiic controlling deviceby. said lever, under. certain trafiic conditions and thereafter irrespective of trafiic conditionsunless said-lever! is operated aftertraflic conditions have again changed comprising; a slow acting relay, and' a stick relay controlled by said lever andzby said" slow acting relay and in turn controlling'said slow acting relay.

SEDGWICK N. WIGHT. 

